Metallic structural element for buildings.



N0.'84 0,053. PATENTED JAN. 1, 1907-.

. H. L. DUNN.

METALLIC STRUGTURALELEMENT FOR BUILDINGS.

' APPLICATION FILED JULY 31. 1905."

i I g 7 1K 24 1 3 E No. 840,053. PATENTED JANE-1907.

ILLQDUNN. METALLIC STRUCTURAL ELEMENT E E EUILDINGE.

AYRLIOATION FILED JULY21,1905.

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HE ERTTL. DU N, or HOPEDALE, MASSACHUSETTS.

' METALLIC STRUCTURAL ELEMENT on BUILD Specification of Letters Patent.

rammed Jan. 1, 1907.

Application filed July 31. 1905. Serial No. 272,029.

To all whom it'm/ay concern.

Be it known that I, HERBERT L. DUNN, a citizen of the United States, and a resident of Hopedale, county of Worcester, State of Massachusetts, have invented an Improvement in Metallic Structural Elements for Buildings,&c'., of which the following description, in connection with the accompanying drawings-is a specification, like characters on thedrawings representing like'parts.

This invention relates to the so-called composite;construction for buildings, col- I, umns', and various structures in which a metallic skeleton framework is used in. combination with a concrete or similar filling; and it has for its object the production of a novel, simple,fand eflicient structural element for use .in'connection with such structures. I These elements assembled in various forms', a vastnumber of which are possible, .areused as a reinforce'me'nt for'the concrete or other filling material in constructing foundations, walls, columns, beams, floors, &c.

The. structural element embodying my invention consists of'a metallic bar or rod of suitable dimensions bent or deformed to present substantially trapezoidal convolutions, the bases of adjacent convolutions being located in and forming the upper and lower chords of a truss-likestructure when used with tie-rods, the inwardly-converging sides of the convolutions connecting the chord portions and forming the diagonals of the structure. Such formation of the structural element provides, when a number of such elements are assembled, locking-openings through which tie rods are passed, tying the whole into a strong ri id skeleton frame self-sustaining and capab e of imparting to the" filling great resistance to tensile strains.

In assembling the elements they are arranged in couples, as it were, the convolutions of one being opposed to or the reverse of the convolutions of the other, so that the bends conneotin' the base and sides of a convolution in one e ement overlap bends in the coupled element. Through these overlapped bends the tie-rods are passed and resist extension longitudinally in "either or both chords, as the case may be. I

The convolutions of an element are preferably symmetrical with relation to the median line of the element, so that the elements are reversible and interchangeable for a given size.

A combination of a plurality of longitudinal elements with the transverse tie-rodsproduces a firm species of netting having length, breadth, and thickness or depth, tied securely together without the use of wire Wrappings, clips, or welds, self locking and sustaining, and possessing great firmness and stifiness.

The varous novel features of my invention will be fully described in the subjoined specification and particularly pointed out in the following claims.

Figure 1 1s a side elevation of a portion of a structural element embodying my invention. Fig. 2 is a similar .view showing a plurality of elements coupled together with tie rods in the lower chord only of the truss formation. 'Fig. 3 is a top plan view thereof. Fig. 4 is a view similar to Fig. 2, but showing tie-rods in both chords, the filling of concrete or other suitable material being indicated by dotted lines. Fig; 5 is a perspective view of a concrete beam reinforced by a skeleton frame made up of structural elements embodying my invention. Fig. 6 is a transverse section of such'a composite beam on the line 6 6, Fig. 4, looking toward-the right.

Fig. '7 is a perspective view illustrating a beam and floor structure embodying the novel structural elements. Fig. 8 is a top plan view of a skeleton frame suitable for a floor, wall, or partition, showing stiffeningbinders. Fig. 9 is a side elevation thereof,-

but with the longitudinal elements in dotted lines and the binders in full lines. Fig. 10 is a perspective viewof a composite column structure, showing the manner in which the structural elements can be arran ed to sitifien and effect lateral bracing of the filhng. Fig. 1 1. is a transverse sectiona view thereofthrough the framework.- Fig.'1 2 is an enlarged spective view of a skeleton frame assein led I and made u of the structural elements and tie-rods, wit an eyebar formof stiffening binder; and Fig. 13 an enlargeddetail of the opposite bends a the ends ofone of the loo sides common to two adjacent convolutions of the structural element. Fig. 14 is a sectional view of a concrete floor, showing the use of the'elements without tie-rods, serving to bond together the foundation or bottom 105 and'the top or wearing surface. Fig. 15 is a transverse section on line 15 15, Fig. 14.

Fig. 16 is a plan view of a brick wall with an air-space, showing the use of the elements to tie t e two parts of the well together. Fig. 1 1o 17 is a transverse section on line'17 17, Fig. 16. Fig. 18 is a partly-perspective view showing the use of the elements by themselves acting as binders in a pavement struc- 5 ture of concrete.

In making up the structural element in accordance withmv invention I take a metal bar or rod, preferably cylindrical and of proper diametersay about two inches,

more or less-and deform or bend the same to form substantially trapezoidal convolutions A B, the former being reversely arranged with relation to the latter. Each convolution comprises a base ortion 1 and sides 2, shown herein as inward y convergent,

connected with the ends of the base by circular bends 3. I prefer to make thesebends with. radius equal to one-half the diameter of the'element plus one-half the diameter of the transverse tie bar or rod t, to be referred to,

and, viewing Fig. 13, the radius r ofcurvature of the bend 3 is equal to one-half the diameter of the; bar a (the element) plus one-half the diameter of the tie-rod t. This 2 5 rovides fora snug fit of the tie-rod in the liend when the' elements are assembled. With reference to the median line of the element, which may be made. of any convenient length, (said line being indicated at m m, Fig. 1,) the convolutions A may be con sidered to be one series above the line and the convolutions B a second series, alternating with series A and below the median line, the inclined sides of a convolution in one 5 series merging into or being coiinnon with a side of each of two convolutions-in ln other series. A truss-like structure is the: formed when used with tie-rods, the bases 1 ofseries A forming one chord and the bases of the.

40 other series B forming the other chord, the

inclined sides 2 of the trapezoidal convolutions connecting the chords and constituting diagonals of the truss. In assembling these elements there is almost an infinite number 5 of ways in which they cam be arranged, and I have shown herein but aifew exam les of the skeleton frame or structure whic can be the character and utility of the invention. I have also shown some examples in which the elements are used without tie-rods. Referring to Figs. 2 and 3, a plurality of the structural elements made as described are arranged in parallel planes, laterally sep- 5 5 arated and so placed that the convolutions of one element break joints, as it were, with the convolutions of adjacent elements. The

V elements a Fig. 3, alternate with elements b", and the bases 1 of the convolutions of the former afe locatedo posite the spaces between the bases of t 1e convolutions of the elements b the bends 3 at the ends of the bases overlapping or extending past each other. By this arrangement openings are 6 5 formed through-which transverse tie'rods t tributed throughout the cross-section of the sections at widely-distributed points.

are passed from one to the other side of the frame, and in Fig. 2 the tie-rods arepassed through the dpenings the lowerchords only, though it will be seen that .the open-; ings 4, formed in theupper chords, could be utilized in a similar manner. Such an'arrangement is shown in Figs. 4;, 5, and 6', the tie-rods t being located in the lower chordopenings and the tie-rodst' the upper chord-openings.

In Fig. 3 the elements are shown as e uidistant from each other laterally, and a jacent elements may be said to be coupled together by the tie-rods, the elements of a couple being reversed as to the location of the1r convolutions, as ex l'ained.. If desired, however, two or more e ements placed side by side may make one member of a couple, anda like number of. reversed elements may make the other member, as will be manifest.

Referring to Figs. 5,and 6, it will be noted that the coupled members are laced close together and one of the cou les is separated laterally from the other oofip e, the similarlydisposed members a being arranged on the outside, with the corresponding members b inside. i i

A strong, rigid, yet light, skeleton frame is thus prov1ded,-self-loeking and self-sustainin and adapted to form the framework or 5 re nforce for the concrete or other filling F, herein shown as molded about the metallic frame to form a composite beam.

When the elements are thus formed into a self-sustaining structure by the tie-rods, which latter lock the elements together, so rigid a truss structure is presented that the molds for the fillin can be attached directly thereto, greatly re ucing the cost of building and supporting the formsor boxes in which the concrete is molded. a A strong and rigid reinforce for the concrete is provided without the weight and expense or the regular structural sections, such as I-beams, &c., and a most thorough and complete mechanical bond between the fill- IIO ing and the reinforcing-frame is assured by made, suflicient, however, to demonstrate" the form of the latter and the parts composing the same, It will also be seen from an inspection of Fig. 5 that the reinforce is Well disfilling instead of being concentrated in heavy Consequently there are no planes of weakness, as the frame reinforces the entire section.

The skeleton frame or reinforce resulting from the combinationof the structural ele ments with the transverse looking or tie rods has two parallel surfaces strongly supported andfirmly held together without the use of any additional members, as will be manifest. One of these surfaces affords suitable reinforcement for the floor when used in a building, while the other surface may be used for the ceiling, and by the use of a proper mold 130 surfaces.

an; air-space may be 3 Thepeculiartruss formation or arran ement of. the reinforce-produced by the pecu iar deformation or bending of the rods or bars to e form the structural e ments in my invention not only gives a rigid reinforcement to the filling, with a perfect mechanical bond, well distributed and adapted to many uses, but it places the metal where it is most necessary to overcome tensile stresses by giving a continuous tension member throughout the structure.

When a block of concrete is subjected to a compression test, it fails by the sides spalling off, as there is nothing to' holdthe sides from bulging. The inclosi ng jacket formed by the elements in accordance with my invention gives a lateral supplort to the filling, which greatly increases t e resistance thereof to compression.

In Fig. 7 I have shown at D a reinforce or skeleton frame embodying my invention for use as a floor-beam and sup orting a composite flooring comprising filing F and a skeleton frame or reinforce such as has been described, the filling for the beam being indicated by dotted lines at F. The reinforce D in the-beam is substantially the same as shown in Fig. 5; but the upper tie-rods are omitted, as the tie-rodsin the lower chords resist the tensile strain on the beam.

In Figs. Sand 9 I have shown a skeleton reinforce or frame substantially such as illustrated in Fig. 5 so far as relates to the cou pled structural elements a b arranged in pairs; but I have provided stifiening-bindmade with larger convolntions.

ers which partake of the general characteristics of the structural elements; but they are The outsidebinders are made with alternating convolutions'S 9 of such length that they come 'spond to a number of the smaller convolu- .tionslof theregular' elements a b that is,

p 1 as shown, one of the binder convolutions will span sixof the tie-rods in a chord, while the ordinary convolutions span but two tie-rods.

Intermediate stiffening binders are also shown, a pair of them being illustrated in Fig. 8-side byside andlbetween thetwo pairs of coupled elements, and the convolutions h ere are a combination of small and large ones that is, the convolutions 1O 11 are large enough to span, say, four of the tie-rods and the intervening smaller convolutions 12 13 span buttwo of the tie-rods.

The stiffening-binders serve to strengthen and stiffen the frame as a whole, and they formed between such may be shaped diflerently and applied in different waysas, for instance, they may be made as eyebars (see Fig. 12)the binders 14 having eyes 15 to receive the tie-rods t in the upper chord, and in this illustration the binders strengthen the lower chord of the truss-frame by passing beneath tie-rods t in such lower chord.

My invention is readily adaptable to various usesas, for example, the same general form of structural element such as shown in Figs. 1, 2, 5, and 7 may be used in a foundation, column, beam, or floor, but the combining or assembling would be varied to suit the conditions in each case. For instance, in Figs. 10 and 11 an arrangement is shown suitable for a column, the several elements, deformed or bent as hereinbefore described, being set upright in a series of radial planes, but reversely, as before explained, in order that the tie-rods may lock them together. The tie-rods t in this instance are bent into circular form and lie in horizontal planes, and while I have shown them only at the outer edges of the elements it will be obvious that other tie-rods curved on a smaller radius can be used on the inner edges. The filling is indicated at'F and the elements as a whole at a In general the convolutions in the ele.

ments are made symmetrical, with the bases of the convolutions forming one series alined and parallel to the-bases of the other series of convolutions, and then the oppositely-turned bends 3 at the ends of a-common side member 2 will be struck from centers which lie in a line normal to the chords of the structure,

as shown in Fig. 13, the line 30 passing through the centers 31 of the upper and lower bends shown and being normal to the upper and lower chords. This line 30 also inter- -sects the common side member 2 at its cen ter. The deformation or bending of the ele ment may be variedsomewhat, however, for particular cases, and the disposition of the reinforcement is at the will of the designer to suit the conditions of the case.

When the elements are assembled to form a reinforce or frame for concrete-steel construction, as in columns, beams, &c., short lengths only are exposed to the heat 'in case of fire, and consequently there is no chipping or spalling off of the concrete, as is the case when continuous rods or bars are used, due

to the expansion of the same practically as a unit.

My invention results in eat economy of construction, as the deformin or bending of the bars or rods to form the e ements canbe effected at a very sli ht increase over the cost of the steel, and tl ie assembling into the desired frame is easily accomplished. There is also a saving of cost on the forms requisite to mold the filling, and the latter can be easily placed about the reinforce without danger of voids. A very simple and effectthe structural element may be used without tie-rods to tie or bond different parts together. In the construction of a concrete floor it is often desirableto make the upper or Wearing surface of a richer mixture than the bottom or foundation; but it has been difiicult to make a satisfactory bond between the two layers. I have found, however, that by using my structural elements in the manner shown in Figs. 14 and 15 a most perfect and thoroughly satisfactory bond 15 provided. The elements are placed in parallel vertical planes, but preferably with openings in one opposite closed portion of the next element, the lower portion of each element being embedded in the foundation layer.

The wearing-surface or top layer is then applied and embeds the upstanding portions of the elements.

In Figs. 16 and 17 I have shown the use of the elements to tie the two portions of a brick wall built with an air-space, the elements being laid between courses in parallel horizontal planes and breaking joints, as shown.

A very simple, cheap, and strong tie is thus provided. Another use is shown in Fig. 1,8, the elements being embedded in the concretepavement structure and set in parallel upright planes, the elements being capable of bending to conform to the general conformation of the concrete. The convolutions of the elements act in such a structure to securely bind and hold together the various portions of the concrete, givinga very strongi tions having mwardly-converging sides, the

and wear-resisting body.

Having fully described my invention, What I claim as new, and desire to secure by Letters Patent, is-

-1. A reversible structural element for buildin purposes, consisting of a metallic rod or ar deformed or bent to present two alternating series of convolutions having straight base portions and inwardly-convergent sides, the centers of curvature of corresponding apex bends of two adj acent convolutions lying in a line perpendicular to the base portions and intersecting the common side of said convolutions at itseenter, said bends be I pairs of tli e latter eing therebylocated one above the other in lines perpendicular to the base portions.

2." A structural element for building purada ted to receive tie-rods,

poses consisting of a metallic rod'or bar deormed or bent to-present substantially'trapezoidal convolutions lying n the same plane,

the dia onal sidecommon to adjacent convo- .present spbstantially trapezoidal convolutions having inwardly-converging sides, the convolutions pf adjacent elements being reversed to cause the bends at the ends of their bases to overlap, and a filling in which the eing adaptedto receive cylindrical tie- I said elements are embedded, the elements reinforcing and bonding the filling.

4. A skeleton frame. for composite structures, comprisin a plurality of elements each consisting o a metallic rod or bar bent to present two alternating series of convolutions havin straight base portions and sides joining the ases by circularly-curved bends,

the convolutions of coupled elements being reversely positioned to cause the bends at the ends of their bases to overlap, and cylindrical tie-rods passed through the pairs of overlapped-bends and being seated therein, to unite the elements into a rigid frame.

5. Askeleton framefor composite structures, comprising a plurality of elements each consisting of a metallic rod or bar bent to present substantially trapezoidal convolutions having inwardly-converging sides, the convolutions of coupled elements being reversely positioned to cause the bends at the ends of their bases to overlap, and tie-rods passed through the pairs of overlapped bends to unite the elements into a rigid truss-like frame 6. A skeleton frame for composite structures, comprising a plurality of elements each consisting of a metallic rod .or bar bent.

to present substantially trapezoidal convoluconvolutions of coupled elei'nents being reends oftheir bases to overlap, and tie-rods passed through the pairs of overlapped bends to unite the elements into a rigid frame, combined with stifi'ening-binders bent to present elongated trapezoidal convolutions equal to two or more convolutions of one of said elements and cooperating with predetermined tie-rods.

7. A skeleton frame comprising a plurality v of metallic rods or bars'each bent to present substantially trapezoidal convolutions havsmote ing inwardly-converging sides, the convolutions of coupled'elements being reversely positioned to cause the bends at the ends of their bases to overlap, and tie-rods passed through the overlapped bends transversely of the elements, to unite the same into a rigid structure, and a filling of plastic or cementitious material.

8. In building construction, a composite structure comprising a skeleton frame consisting of coupled elements, each element consisting of a metallic rod or bar bent to present substantially trapezoidal convolutions having inwardly-converging sides and their bases forming upper and-lower chords, the tWo elements constituting a couple being reversely positioned to cause the bends at the ends of the bases of the convolutions to overlap", and tie-rods passed through the pairs of overlap ed bends in both chords of the elements. orming a couple, to thereby form a rigid frame, and a filling.

9. A skeleton frame com rising a plurality of metallic bars or rods eac bent to present substantially trapezoidal convolutions hav ing straight base portions constituting upper, and lower chords, and inwardly-convergmg sides connecting them, the convolutions of adjacent elements being reversed to cause the bends at the ends of their bases to overlap, and tie-rods passed through the over lapped bends, to tie or bind the elements into a rigid structure, and a filling in which the said elements and tie-rods are embedded.

10. A self-sustaining skeleton framework for composite structures, comprising a plurality of elements located in different planes-and nating convolutions to overlap, and tierods extended through the overla ped bends, to unite the elements into a rigi unitary trusslike frame.

11. A seli-sustaining skeleton framework for composite structures, comprising a plurality of elements located in different planes and each consisting obey -metallic rod or bar bent to present substantially trapezoidal v 575 convolutions having straight bases endin:

weirdly-converging sides, the bases in one chord of the elementbeing alined and inparallelism with the bases in the other chord ad'acent elements being reversely positionedto cause the bends at the ends of the bases of,

alternating convolutions to overlap, and two sets of tie-rods, the tie-rods of each set passing through the overlapped bends in one of the chords, to thereby unite the. elements at both chords and resist fiexure transverse to the depth of the elements.

In testimony whereof I have sig'nedmyname to this specification in the presence of two subscribing itnesses.

HERBERT L. DUNN.

Witnesses: 4

WALTER F. Rornn, CLARE H. DRAPER. 

